【Save Time & Money】With one core drill bit and the chamfer bit, you can create many different hole sizes, no need to purchase several bits. 【Application】enlarge/shape/round the EXISTING HOLES. Reduce the risk of cracking with standard and large format tiles subjected to tension (ex tightened plumbing, led lights etc),Bevel Ease chamfers and stress relieves rough holes in glass, ceramic and porcelain tiles 【Attention】This diamond beveling chamfer bit can NOT be used to drill holes, only to enlarge, shape, or round bevel existing holes. And it can be used with water or not, very easy to operate. 【Machine】 --Angle grinder 5/8-11 thread or standard drill(electric drill,hand drill, or other machines that accept round shank.）